548 



Professor Dewar 



[June 11, 



To clear up this matter still further, about 10 grams of the original 

 nodule were digested with pure ether in the way described by 

 Lawrence Smith for extracting the hydrocarbon-like bodies. It was 

 allowed to stand for twenty-four hours with excess of ether, and then 

 filtered, and washed with more ether. The graphite thus treated was 

 dried at 110° C, and the gases extracted from it. 



For the purpose of comparing one of the terrestrial graphites 

 with the above in regard to its behaviour with ether, the specimen 

 of unknown origin was selected, as yielding the largest quantity of 

 marsh-gas. The residue, after digestion with ether, was dried, and 

 the gases pumped out as before. 



It will be seen that by this treatment with ether the volume of gas 

 given off by the celestial graphite, and also the marsh-gas, have bee a 

 reduced to rather more than one-half, while with regard to the un- 

 known graphite, although the total volume of gas remains about the 

 same (probably due to a rather higher temperature being employed), 

 the marsh-gas has also been reduced to rather less than one-third 

 the original amount, and the hydrogen has correspondingly increased. 



These experiments prove that either the ether did not dissolve out 

 all the actual carbonaceous compounds present, or that the marsh-gas 

 was subsequently formed during the heating of the graphite. 



As Dr. de la Eue had kindly placed at Professor Dewar's disposal 

 a splendid specimen of the Orgueil meteorite, the opportunity was 

 taken of comparing the gases occluded by this typical specimen of 

 the carbonaceous class with those obtained from the stony meteorites 

 and the graphites. This meteorite has been so thoroughly examined 

 by Cloez and Pisani (Compt. Kend. vol. lix. (1864) pp. 37, 132) 

 with regard to its chemical inorganic constituents, that nothing need 

 be said as to its general composition. The investigation was there- 

 fore confined to the gases given off on heating which had not pre- 

 viously been determined. 



During the heating of the meteorite a large quantity of water, on 

 which floated numerous small pieces of sulphur, collected in the bulb 

 tube immersed in the freezing mixture. This water was strongly acid, 



